Would you be more likely to get a vaccine if there weren’t any needles involved in the process? Well, according to researchers who administered vaccines to mice via dental floss in a new study, the future looks promising. This needle-free vaccine delivery technique stimulated a strong response in mice against deadly influenza infection. How does a dental floss vaccine without needles work, and would it make more people decide to get vaccinated?
How Would a Dental Floss Vaccine Work?
Vaccines are typically administered in the form of one or several injections. These types of vaccines are generally effective, but there may be scenarios where alternatives to injections would be beneficial. Previous studies have already indicated that the mouth is an ideal place for vaccine delivery. Not only do oral vaccines trigger immunity in the bloodstream, but also in the mucosal tissues where viruses often enter the body. However, experiments to try to deliver the vaccines under the tongue or to the cheeks had had mixed results.
For this new study, researchers from North Carolina State University sought to determine if the gums were a suitable site for vaccine delivery. They specifically looked at the little groove between the gums and teeth called the gingival sulcus. The junctional epithelium is the thin tissue lining at the base of the tiny groove. This tissue is more permeable than other tissues, which is what made it such a good candidate for a dental floss vaccine delivery. Using flat tape dental floss bought from a local pharmacy, the team flossed the teeth of mice in the lab after coating the floss with various vaccine molecules.
Findings of the Study
The researchers found that the proteins, peptides, and inactivated influenza viruses all effectively transferred into the gum tissue of the mice. The needle-free vaccine delivery system stimulated the production of antibodies and immune responses in the lab mice. They further observed antibodies in the bloodstream, mucosal surfaces, and significant immune activity in multiple organs. After that, the researchers wanted to find out whether the dental floss vaccine protected the mice from potentially deadly influenza infection.
They found that the mice were fully protected and that it was more effective than experiments involving delivery under the tongue and inside the nose. According to the study’s lead author, Rohan Ingrole, “We found that applying vaccine via the junctional epithelium produces far superior antibody response on mucosal surfaces than the current gold standard for vaccinating via the oral cavity, which involves placing vaccine under the tongue. The flossing technique also provides comparable protection against the flu virus as compared to the vaccine being given via the nasal epithelium.”
Promising Results
The team then wanted to find out how this approach would work in humans. So, they took off-the-shelf dental floss picks, coated them with fluorescent dye, and tested them on 27 individuals. The researchers discovered that the picks managed to deliver the dye to the junctional epithelium successfully. A subsequent survey given to the participants indicated that the floss pick technique was well-received. This needle-free vaccine delivery system could offer a practical alternative to traditional vaccines.
They would require little preparation and would be painless, taking the hassle and fear out of the usual needle-based vaccines. They also don’t require refrigeration, which would potentially make them easier to distribute and more affordable. The next step is to find out how well dental floss vaccines stimulate immune responses in human subjects. Additionally, they also want to learn if these vaccines can be used by those with gum disease. The team is not yet sure if this delivery method would work in young children who don’t have teeth yet.
The Bottom Line
So far, the study has indicated that an oral vaccine without needles is not only possible, but effective. As the head researcher, Dr. Harvinder Singh Gill explained, “This is extremely promising, because most vaccine formulations cannot be given via the nasal epithelium – the barrier features in that mucosal surface prevent efficient uptake of the vaccine.” While experiments that delivered vaccines under the tongue and to the cheeks have shown mixed results, this new needle-free vaccine delivery system to the gums is showing great promise.
The next step is to see if those same results from mouse studies will be observed in human trials. So far, coating the floss with fluorescent dye has been shown to be effectively delivered to the junctional epithelium. This is a good indication that vaccines would reach their target as well. However, researchers are still unsure if this delivery system would work with kids that don’t have any teeth. For now, the results look promising, and hopefully, subsequent studies will prove their safety and efficacy and will then be made available to the public at large.